Fabrication, functionalization and applications of cellulose based aerogels: A review

Cellulose based aerogels have recently gained a lot of interest in the past few years because of their sustainability, biocompatibility, biodegradability, and biosafety. Cellulose is an excellent raw material for the preparation of aerogels because of its advantages of strong renewability, low cost, good biocompatibility and easy degradation. The nanoscale cellulose can be prepared by physical, chemical and biological enzyme methods for the preparation of nanocellulose based aerogels (NCBAs). As a third-generation aerogels, NCBAs have the advantages of high porosity, large specific surface area, low density, low dielectric constant and high adsorption, which have many potential applications in adsorption, insulation, energy storage, electromagnetics, and biomedical fields. Here, the recent reported preparation technology of nano-cellulose and NCBAs were reviewed, the preparation methods of cellulose nanocrystals, cellulose nanofibers, and bacterial cellulose were highlighted. Furthermore, the research progresses of manufacturing and applications of functional cellulose hydrogels in the field of dye adsorption, oil adsorption, heavy metal ion adsorption, carbon dioxide adsorption, thermal insulation applications, energy storage, electromagnetic interference application, and biomedicine application were reported comprehensively. Further insights into the future research direction of NCBAs were provided.